As competition for health care services increase, understanding the relationships among interventions and patient outcomes is essential. Nursing interventions are not accounted for in standardized coding schemas, and, thus, are rarely included in outcomes effectiveness studies that use large electronic data sets. The recent implementation of standardized classification systems of nursing interventions, such as the Nursing Interventions Classification (NIC), now makes it possible to describe the contributions of nursing care to patient outcomes. Research in this area has been limited due to availability of clinical data repositories that include nursing care variables. The site for this proposed study, the University of Iowa Hospitals and Clinics (UIHC), has a large electronic database of nursing interventions accumulated over 3 years that can be accessed and linked, at the individual patient level, to other clinical and operational data. The purpose of this 4-year exploratory study is to evaluate a methodological approach for conducting nursing outcomes effectiveness research using existing clinical and operational data that reside in several electronic data repositories in a large academic medical center. Specific variables will be identified and examined in three elderly patient groups: DRG 127 - Heart Failure and Shock, DRG 209 - Major Joint and Limb Reattachment Procedures of the Lower Extremity (Hip Fracture), and those who are recipients of the nursing intervention Fall Prevention. The process and results of this study will be used to formulate a guideline for investigators on the construction and use of a nursing effectiveness research database built from electronic data repositories. The study's four aims are to: Identify the most frequently used nursing diagnoses, nursing interventions, pharmacological treatments, and medical treatments for the hospitalized elderly with DRG 127 or 209, and for those who receive the NIC intervention of Fall Prevention. Describe the relationships among patient characteristics, patient clinical conditions (nursing diagnoses, medical diagnoses, severity of illness), treatments (nursing interventions, medical treatments, pharmacological treatments), characteristics of nursing units, and outcomes of hospitalized elderly patients (DRG 127; DRG 209, Fall Prevention) using a cross sectional, retrospective design. Compare the cost of acute care for patients a) who receive of the nursing treatment Fall Prevention with those who do not receive this nursing intervention, b) who receive the most frequently used nursing treatment for heart failure (DRG 127) with those who do not receive this intervention, and c) who receive the most frequently used nursing treatment for hip fracture (DRG 209) with those who do not receive this intervention. Develop a guideline for construction and use of a nursing effectiveness research database built from electronic data repositories.